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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, yet the description still adds real context: no account or token required, and a citation rule that presentation_text is not official wording. It does not cover behavior on an invalid or unknown id.

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?

Four short labeled fragments — purpose, when-to-use, notes, example — with zero filler and the essential 'return one clause card by id' front-loaded.

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 tool with annotations and an output schema, the description covers purpose, ordering relative to search_clauses, auth expectations, and a citation caveat. Only error/not-found behavior is left unspecified, which is a minor gap.

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%, so baseline is 3; the description adds the provenance of the id ('stable id', obtained from search_clauses) and a concrete example argument matching the pattern, which helps an agent construct a valid call.

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 and resource — 'Return one clause card by stable id' — and enumerates what the card contains (official paragraph, conditions, exceptions, definitions, links, errata). An agent can distinguish it from search_clauses purely from this sentence.

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?

Explicit sequencing guidance: 'Use after search_clauses when you need the whole paragraph or its exceptions before answering,' which names the alternative and the condition that selects this tool. It lacks an explicit when-not or a second alternative, so it falls short of a 5.

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