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

The annotations already cover the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=false), so the description's job is to add context, and it does: it explains that results are returned best-match-first and that the limit is ignored when the query is empty, plus what each returned pattern contains. It doesn't discuss pagination or result size beyond the limit, which keeps it off 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?

It's two sentences and front-loads the count and identity of the patterns before moving to how to query them. The run of illustrative examples ('giving the facts, naming the reader, showing one example…') is a little list-heavy, but each example clarifies the resource rather than padding it.

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, annotations covering safety, and 100% schema coverage, the description needs only to orient the agent, and it does: what the catalog is, what each entry holds, and how to query or list it. The one thing missing is any routing hint against the other prompt-related siblings.

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% and both parameters are already documented in detail, including the note that the limit is ignored when the query is empty. The description reinforces the query semantics with examples ('stop it inventing numbers'), but adds no constraint or format detail the schema lacks, so the baseline 3 applies.

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?

It clearly states the resource (the 24 prompt patterns from thinkhard.si) and what each record contains: when it helps, when it does not, a before-and-after pair with scores, and the line to add. That's a specific verb-plus-resource picture an agent can act on. What it doesn't do is distinguish itself from close siblings like get_prompt or search_prompts, so it stops short of a 5.

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 second sentence gives concrete query guidance (search by pattern name or by the improvement you want, leave empty to list all 24), which implies the right usage pattern. But it never says when to prefer this over search_prompts, get_prompt, or grade_prompt, so the agent has to infer the choice from sibling names alone.

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