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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: the no-query call is 'cheap' and returns a section index, results are limited to matching sections only, and the ~150 KB cost of the alternative is quantified. It stops short of noting rate limits or result truncation, so not a 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?

Four tight sentences, front-loaded with the core action and scope, then the two invocation modes, then the cost rationale and the alternative tool. Every sentence carries routing or behavioral information with no filler.

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?

No output schema exists, but the description characterizes the return shape (matching sections only vs. a section index) and names the sibling tools that cover the remaining needs. For a two-parameter read-only search tool, an agent has everything required to call it correctly.

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 coverage is 100%, so both parameters (limit default 3/max 5, query maxLength 256) are already documented — baseline 3. The description still adds value: a concrete query example ('isr revalidate') and the semantic consequence of omitting query for a cheap index, which clarifies intent rather than restating types.

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 (Search) and resource (nifra's framework documentation) with explicit scope: returns ONLY matching sections, with a no-query index mode. It explicitly distinguishes itself from sibling nifra_types (exact TypeScript) and from reading llms-full.txt, so an agent can route without opening any schema.

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?

Gives explicit when-to-use for both invocation modes (no query = cheap index; query = top matching sections) and names the alternatives not to use: nifra_types for exact TS, and llms-full.txt as the expensive path. Nothing about selection is left to inference.

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