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

Annotations already declare read-only, idempotent, closed-world behavior, so the safety profile is covered. The description adds the ranking rule ('closest first') and the matching criteria (tags + section), which is genuinely useful, but says nothing about behavior for unknown ids, empty results, or per-locale matching.

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?

A single short sentence with zero padding, and the matching basis and ordering come early. It loses a point only because the fragment form reads as a caption rather than a self-contained instruction.

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?

An output schema exists, so return values need not be explained, and annotations cover safety. What remains missing is routing guidance against the many sibling discovery tools and any hint about the 'limit' parameter, making it only minimally sufficient.

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 67%: 'id' and 'locale' are documented, but 'limit' has only type/default/max with no prose anywhere. The description mentions no parameters at all, so it does nothing to close the remaining gap or clarify what 'closeness' means for results.

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 fragment 'Pieces that share tags and section with a given piece, the closest first' does convey the retrieval concept and its similarity basis, but it is a noun phrase with no verb and no differentiation from siblings like 'search' or 'series' that could also surface related content.

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?

There is no statement of when to pick this over 'search', 'series', or 'list_tags', and no prerequisites (e.g. that the id must already exist or came from 'fetch'). The agent must infer usage entirely from the name.

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