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

Annotations already declare readOnly, openWorld, and idempotent hints, but the description adds substantive behavior beyond that: returns passages with character offsets and similarity scores, uses BGE-base-en embeddings with cosine similarity over 500-character overlapping windows, and enforces a 200K character cap with truncation flags. These are valuable operational details not inferable from annotations.

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 dense sentences deliver purpose, use case, companion tool, and technical caveats without fluff. The description is front-loaded with the core action, then progresses logically to when and how to use it, ending with constraints. Every sentence earns its place.

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 compensates by explicitly stating the return payload: 'top-N passages with character offsets and similarity scores.' It also covers edge-case behavior (truncation over 200K chars) and the embedding/windowing approach, giving the agent a complete mental model for planning calls.

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 parameters are well-documented structurally. The description reinforces the meaning of 'text' ('you already pulled') and 'query' (natural-language with examples), adding pragmatic context. However, it doesn't elaborate on 'limit' beyond the schema, though the schema itself already explains its range and default.

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 'Semantic search INSIDE a fetched record,' which immediately identifies a specific verb, resource, and scope. It clearly distinguishes this tool from siblings like 'search' and 'ask_pipeworx' by emphasizing that it operates on already-fetched text rather than external sources.

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 guidance is provided: 'Use when the record is too big to cram into the prompt.' It also names a complementary tool, 'ask_pipeworx_grounded,' and explains the pairing: 'fetch with the gateway, ground over the relevant passages instead of the whole document.' This gives clear when-to-use and when-not-to-use context.

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