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

readOnlyHint=true already establishes the safe-read profile, so the description's added value is its disclosure of what the response contains (the estimate's options and each option's approval status) plus the underlying API route. It does not cover not-found/error behavior, but it usefully offsets the absence of an output schema.

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 action and return contents. The trailing 'Housecall Pro: GET /estimates/{estimate_id}' is mildly redundant but earns a little place as API-mapping context.

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 no output schema, the description carries the burden of describing returns and does so (options and approval statuses). For a simple one-parameter read tool this is nearly complete, with only error behavior left implicit.

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 required estimate_id is already documented in the schema; the description only restates 'by id'. Baseline 3 is appropriate since the schema fully carries parameter semantics.

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 (Fetch) and resource (a single estimate by id), and clarifies it returns the estimate's options and each option's approval status. The word 'single' plus the 'by id' qualifier cleanly separates it from sibling housecall_list_estimates.

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 'by id' framing implies this is the single-record lookup versus the list_estimates sibling, but the description never explicitly says when to use this versus listing or creating estimates. Usage is left to be inferred from the name and schema.

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