Get invoice settlement

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows this is a safe read. The description adds nothing beyond 'Fetches one settlement' – no mention of error behavior, empty results, or what constitutes a settlement. It merely restates the operation without new context, and the annotation already covers the read-only nature.

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?

A single, front-loaded sentence with zero fluff. States the verb and object immediatelyais entirely concise and gets straight to the point.

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 simple read-only tool with two path parameters, the description is adequate but minimal. It doesn't clarify what a 'settlement' refers to in this domain, nor what the response contains-semantics. Since there's no output schema, adding a hint about the shape or use of the returned data would help, but the core operation is clear enough for basic use.

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%, and both parameters are simple string IDs described only as 'Path parameter'. The description adds no additional parameter semantics, relying entirely on the schema. Since the schema descriptions are minimal and the IDs are self-explanatory in context, the baseline of 3 applies – the description doesn't hinder but also doesn't enrich.

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 ('fetches') and resource ('one settlement on an invoice'), clearly identifying what the tool does. While it doesn't explicitly distinguish it from sibling tools, the scope is precise and understandable. A slight deduction for not contrasting with a possible list-settlements sibling, but the purpose is unambiguous.

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?

No guidance on when to use this tool versus alternatives. It doesn't mention that this is for fetching a single settlement, nor does it point to a sibling for listing settlements. The context that this is the read-single counterpart to a list operation is missing, leaving the agent to infer usage from the name alone.

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