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

With no annotations, the description carries the full burden and does well: it discloses the return shape, states Credential: none and Cost: Free, and flags a non-obvious behavioral caveat — that books from publishers Peregrini does not list as trusted carry a warning the adopter must accept. It does not discuss pagination or error behavior, but for a single-record read that is minor.

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?

Front-loads the intent and then the return payload, with the credential and cost facts compressed into two short clauses. The opening first-person sentence is slightly longer than needed but is not wasteful.

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 one-parameter read tool with no output schema and no annotations, the description supplies the return contents, the trust/warning caveat, and the auth and cost profile. An agent has enough to call it correctly and interpret the response, with only minor gaps like error cases.

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 slug parameter is already fully documented in the schema, including its provenance from house_rules_index. The description adds no syntax, format, or constraint detail beyond what the schema provides, so the baseline of 3 is correct.

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+resource (retrieve one House Rules book) and enumerates what comes back: exact lines, plain-word effects, versions with changes, and publisher. It distinguishes itself from the sibling house_rules_index by making clear it returns one book rather than an index, though the first-person framing ('I want to see...') is softer than a direct specification.

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 phrase 'before my operator adopts it' implies the decision moment when this tool is useful, and the slug source is named. There is no explicit when-not guidance or direct naming of alternatives beyond the implicit index tool.

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