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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds genuine value beyond that by disclosing the return shape (short passages with title, date and source link), which matters because there is no output schema. It stops short of 5 by saying nothing about whether results are ranked, scored, or limited in corpus size.

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?

Three short sentences, front-loaded with the action and resource, then scope, then return format. The opening sentence largely restates the title, which is the only mild redundancy in an otherwise tight definition.

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?

For a two-parameter read-only search with no output schema, the description covers the corpus, the query intent and the result shape, which is close to everything an agent needs. It could still note that results are limited to Kevin's own writing and that the corpus is finite, but nothing essential is missing.

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 the schema already explains both parameters, including the limit range of 1 to 5 and the default of 3. The description adds only the qualifier 'short passages', which does not extend parameter meaning. Baseline 3 is appropriate.

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 a named resource (Kevin's Coaching Brain), then scopes it with the actual content domain: sessions, methods, AI-as-a-coach, match day. The only gap is that it never contrasts itself with the sibling list_sources, so it lands at 4 rather than 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?

Usage is implied rather than stated: by enumerating what the corpus contains, the description tells an agent which kinds of questions will retrieve results. However, there is no explicit when-to-use, when-not-to-use, or reference to list_sources as the alternative for browsing rather than querying.

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