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

Beyond the readOnly/openWorld annotations, the description discloses two non-obvious behaviors: unfiltered search spans all configured sources by default, and hits touching lower-level APIs are withheld unless off_golden_path_reason carries a real justification. That gating rule is exactly the kind of context annotations cannot convey. It does not describe result ranking or trimming, so a 4 rather than 5.

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?

Three sentences, each doing distinct work — scope, source-id discovery, and the withholding rule — with the most load-bearing constraint front-loaded. No filler, though the off_golden_path_reason clause is dense and slightly tangled by nesting the requirement inside the same sentence as the restriction.

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 an output schema present the description needn't explain return values, and annotations cover the safety profile, so the remaining burden is behavioral and parametric. The unusual gating behavior is fully explained; the gaps are limit/category_id semantics and any note on result ordering.

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 0%, so the description must carry all parameter meaning. It does well for sources (default = all configured, discoverable via a sibling) and off_golden_path_reason (required when steering off the golden path), but says nothing about limit, query, or category_id, leaving three of five parameters undefined anywhere.

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?

The description opens with a specific verb+resource ("Search cached Learnosity documentation sources"), which is clearly distinct from siblings like read_document and list_docs_sources. It distinguishes discovery from searching by routing source discovery to list_docs_sources, though it never explicitly contrasts against skills_search or read_document.

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?

It gives concrete prerequisites (call list_docs_sources or read learnosity://sources/index to get valid source ids) and states the default behavior when sources is omitted. It stops short of saying when to reach for read_document or skills_search instead, so the alternative-selection guidance is incomplete.

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