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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and destructiveHint=false, covering the safety profile. The description adds useful behavioral detail beyond that: it returns full text plus the source URL for citation, which tells the agent what it gets back and why (citation), supplementing the annotation set.

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 short sentences, front-loaded with the core purpose and followed by a minimal example. No wasted words or redundancy.

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?

With an output schema present, the description needn't document return values, and the rich annotations cover behavior. For a trivial one-parameter lookup tool, everything an agent needs to select and call it is present, including the relationship to the search sibling.

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% and the single 'id' param is already documented with example values in the schema. The description's inline example {"id":"lane:caveat"} largely repeats that schema content, adding no new format or constraint information. 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?

The description states a specific verb and resource ('Returns the full text of one Switchboard Finance document') and ties it explicitly to the search workflow, distinguishing it from the sibling 'search' tool which produces the id. An agent can tell exactly what this does without opening the schema.

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?

'found by search' establishes the correct usage context: run search first, then fetch a single result by id. It does not, however, explicitly state when not to use it or name the alternative (search) as a routing option, so the guidance is implied rather than spelled out.

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