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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint. The description adds significant behavioral context: embedding model (BGE-base-en), similarity metric (cosine), window size (500-char overlapping), character cap (200K chars with truncation flag), and that passages include offset for verification. This goes beyond what annotations provide.

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 description is a single paragraph that is front-loaded with the main idea and packs in essential details (embedding, window, cap, usage guidance) without wasted words. It could be slightly more structured (e.g., bullet points) but remains concise and informative.

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?

The description fully covers what the tool returns: 'top-N passages with character offsets and similarity scores'. It also notes the truncation flag for inputs exceeding 200K chars. Despite the lack of an output schema, the description compensates completely, leaving no unanswered questions about behavior or outputs.

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 parameters are well-documented. The description adds value by providing example queries for the 'query' parameter and stating the default value for 'limit' (5). It also reinforces the character limit for 'text'. These additions help the agent use the tool effectively.

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 clearly states it performs semantic search inside a fetched record to find relevant passages, with a specific verb ('search') and resource ('inside a fetched record'). It distinguishes itself from siblings by explicitly mentioning the pair with ask_pipeworx_grounded, indicating when to use which. The title 'Search Within a Source' reinforces the purpose.

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 explains when to use the tool: 'Use when the record is too big to cram into the prompt — search_within saves context'. It also mentions pairing with ask_pipeworx_grounded. However, it does not explicitly state when not to use it or provide alternatives beyond the one sibling, which keeps it from a 5.

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