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

Beyond the readOnlyHint annotation, the description adds significant behavioral detail: keyword queries match body text with snippets, umbrella tags expand to members, results are sorted by date descending, and pagination is available. This gives the agent a solid understanding of the tool's runtime behavior.

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 two well-structured sentences, front-loaded with the core purpose, and every clause adds essential detail. There is no redundant or extraneous text.

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 tool with no output schema, the description covers the main contextual needs: what content is searched, filtering behavior, sorting, and pagination. It could also describe the result shape more explicitly (e.g., list of post summaries with title/date/url), but the snippet mention and filter semantics provide reasonable completeness.

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%, but the description enriches parameter meaning: it clarifies that 'query' also searches essay body text (the schema only mentions titles/summaries/tags) and explains that umbrella tags like Policy expand. This adds value beyond the raw schema definitions.

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 the tool's function: 'Search and list blog posts on erikbethke.com.' It uses specific verbs (search, list) and identifies the resource, distinguishing it from siblings like get_blog_post which retrieves a single post.

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 provides context on when to use the tool by explaining its search/filter behavior, including matching body text, tag umbrella expansion, and pagination. It does not explicitly contrast with alternatives, but the guidance is clear enough for an agent to decide when this tool applies.

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