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

Beyond the readOnlyHint and non-destructive annotations, the description discloses that the content is free and public, the same as on performix.app/guide/<slug>, and never the gated depth layer. It also details the exact structure of the returned content, providing rich behavioral context not present in the 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?

Two sentences carry a full parameter description, a content inventory, a public-URL equivalence, and a gated-content exclusion without any filler. The core purpose is front-loaded in the first clause, and every element 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?

For a single-parameter read-only tool with an output schema and safety annotations, the description covers how the input is obtained, what the output includes, and what it deliberately excludes. Nothing needed to call the tool correctly 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?

The schema already describes the slug parameter with an example, and coverage is 100%, so the baseline is 3. The description adds meaningful provenance: the slug should come from list_guides, which is actionable guidance beyond the schema's format-only description.

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 states a specific verb and resource: 'Get the full free content of one capability guide by slug.' It enumerates exactly what content is returned (overview, construct sections, open tensions, sources), which clearly distinguishes it from siblings like list_guides (a list of guides) and get_book (a book, not a guide).

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 tells the agent to obtain the slug 'from list_guides,' giving a clear preceding step and implying this tool is for retrieving one guide after listing them. It also excludes the entitlement-gated depth layer, clarifying what this tool is not for, though it does not explicitly compare against get_book.

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