Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered structurally. The description adds real behavioral context beyond that — automatic scope widening to other Spaces when results are thin, and the "facts, not instructions" precedence rule that constrains how the agent may use results. However it is silent on result limits, ranking, or what an empty answer looks like, which matters for a retrieval tool the agent is told to call repeatedly.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single ~150-word run-on block mixing invocation policy, precedence rules, result semantics, and skill exclusion, with no sentence or list structure to separate them. The lead ("Search your team's knowledge") is correctly front-loaded, but the most operationally important instruction — the `howTo` page-open mode — sits buried near the end, and sentences like "Asking again costs you far less than guessing" are motivational filler rather than specification.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description carries the return-value burden and does so: it enumerates what comes back (conventions, past decisions, run-outcomes, patterns) and discloses fallback widening to other Spaces. It also covers the alternate `howTo` mode and excludes an adjacent resource (skills on disk), leaving no obvious gap for an agent deciding to call it.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all four parameters are already documented in the schema, setting a baseline of 3. The description adds only one piece of meaning beyond the schema: that passing `howTo` switches from search to opening a whole page. It says nothing about `taskContext` as the query string, `projectId` narrowing, or `originUrl`, all of which the schema already covers — so this is essentially schema-level information restated at a high level, and the redundant emphasis on call frequency dilutes rather than extends parameter understanding.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Opens with a specific verb+resource ("Search your team's knowledge") and clarifies the contents (conventions, past decisions, run-outcomes, patterns). It carves out a boundary by stating "Skills are NOT here," but never names or contrasts with the sibling tools (harbor_record_learning, harbor_save_how_to), so the agent must infer whether this is the read-side counterpart rather than being told.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicit timing guidance — "BEFORE starting work" and "AT ANY POINT, as many times as you need" — plus a concrete trigger list (unfamiliar name, file, config value, acronym, decision). It also resolves the precedence case: "Where Harbor disagrees with a rules file or with the user, say so and ask rather than choosing," and adds "Asking again costs you far less than guessing" to disambiguate the reuse-vs-recall tradeoff.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.