get_cost_entry

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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description's only addition is that the resource has no create/update/delete endpoint in Community Edition, which usefully stops an agent hunting for a write tool but is largely a restatement of the read-only hint. Nothing is said about error behavior for a missing id or about pagination/scope.

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 with the core operation front-loaded, and no filler. The second sentence is mildly tangential to invocation but is short and adds context, so it earns most of its space.

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, return values needn't be described, and the annotations cover safety and idempotency. For a single-parameter lookup the description is close to sufficient; the only real gap is how to obtain a valid cost_entry_id and its relationship to list_work_package_cost_entries.

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 0% for the single required parameter, so the description must carry the burden; it only says "by id," which is a restatement of the parameter name cost_entry_id. It adds no format, range, or sourcing guidance (e.g., where to obtain a valid id).

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?

"Get a single cost entry by id" states a specific verb and resource, and the word "single" implicitly contrasts with the list variants among the siblings (list_work_package_cost_entries, get_work_package_costs_by_type). It never names an alternative explicitly, so sibling differentiation is implied rather than stated.

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 implies the lookup use case (fetch one entry when you already have an id) but gives no explicit when-to-use guidance and does not tell the agent to prefer a list endpoint when the id is unknown. There are no stated prerequisites or exclusions.

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