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

Annotations already declare readOnlyHint=true, and the description reinforces this by naming the two GET endpoints used. However, it adds nothing about pagination behavior or result size limits, so beyond confirming the read-only nature it does not deepen the behavioral picture.

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?

Three compact sentences that front-load the purpose before the filtering hint and the underlying endpoints. The endpoint mapping is arguably extra, but it is short and does not dilute the core statement.

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 read-only, three-optional-parameter list tool with no output schema, the description covers what the resource is, what fields it returns, and how to filter. It leaves pagination semantics to the schema, which is reasonable given full schema coverage.

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 page, customer_id, and items_in_page are fully documented in the schema already. The description's 'Pass customer_id for one customer's contracts' duplicates the schema text, adding no semantics beyond the baseline.

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 ('List') and resource ('service contracts'), then enumerates the contract types (retainer, block hours, hourly, remote monitoring) and the data returned (rates, billing periods). No sibling tool covers contracts, so this is unambiguously distinct.

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?

Explicitly tells the agent that passing customer_id scopes the result to one customer's contracts, which is the key usage decision for this tool. It stops short of stating when-not to use it or naming alternatives, but nothing else in the sibling set overlaps.

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