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

Annotations already cover the read-only, idempotent, non-destructive profile, but the description adds meaningful behavior: the return is a plain-text bundle, facets can be absent with a facetNotes entry explaining why, and structuredContent.registration reveals whether analysis is even possible. The only gap is no mention of bundle size limits or truncation for large systems.

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?

The core action is front-loaded in the first clause and every sentence carries information, with no filler. Density is high, though long em-dash-and-parenthetical sentences make it harder to scan than it could be.

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 burden and does: it itemizes the bundle's sections, names the structuredContent.registration flag and its implication, and explains facet absence semantics. An agent can call this correctly and interpret the result from the description alone.

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?

Although schema coverage is 100%, the schema only lists the four enum strings, while the description explains what each yields: 'requirements' gives per-family counts plus FR ids, 'plan' a latest plan summary, 'progress' a modernization rollup, and 'evidence_index' the exact keys accepted by stride.get_legacy_evidence. That is substantial semantic value beyond the enum names.

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?

States a specific verb and singular resource ('Fetch one legacy system') and enumerates the bundle's contents (components, integrations, business rules, data flows, scores, analysis highlights). The singular 'one legacy system' plus the get_ prefix cleanly separates it from the list_legacy_systems sibling, and the mention of evidence keys points at get_legacy_evidence without confusion.

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?

The description implies usage by explaining what each optional facet adds and by noting that a manual system without a connected repo 'cannot be analysed until a human connects one', which is a real precondition. However, it never states explicitly when to call this versus list_legacy_systems, get_legacy_evidence, or get_modernization_repo_status, so the agent must infer the routing.

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