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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds meaningful context beyond annotations: letters are generated from the organisation's own circumstances rather than a shared template, and the service is priced at the organisation tier. It does not, however, describe what the returned details contain or any limitations of the endpoint.

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 longer than necessary for tool selection; the exhaustive list of legal acts (Education Act 1996, Care Act 2014, etc.) is tangential and adds cognitive load. The key usage guidance is placed at the end rather than front-loaded. It is still structured and readable, but tighter wording would earn a higher score.

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 zero-parameter, read-only informational tool with no output schema, the description covers the essential context: what the generator is, who uses it, how letters are produced, legal framing, pricing, and when to choose it over the individual-letter path. It does not explicitly state the return format or contents, which is a minor gap given the description says it 'describes' the generator.

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 tool has zero parameters and the schema is empty, so there are no parameter semantics for the description to clarify. Per the baseline for 0-parameter tools, the description is sufficient and does not mislead.

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 title and description together make clear this tool returns details about StatutoryLetters' organisational letter generator. The description states a specific resource and domain, and distinguishes it from the individual-letter space via the 'rather than an individual complaining to one' clause. However, 'Describes' is a weak verb and it never explicitly states what the caller receives back.

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 gives an explicit condition: 'Use this when the person asking is an organisation sending the letter, rather than an individual complaining to one.' This effectively tells when to use the tool and when not to, but it does not name the sibling alternative (e.g., get_letter_type), leaving some inference to the agent.

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