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

readOnlyHint=true already tells the agent this is a safe read, and "get" is consistent with that. The description adds one useful behavioral detail — that line items come back with the estimate — but says nothing about error behavior for an invalid or unknown hash_key, which matters since there is no 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 with zero waste: the retrieval semantics lead, and the raw endpoint note trails as optional context. Nothing is padded or buried.

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 single-parameter read tool with full schema coverage and a readOnlyHint annotation, the essentials are covered, and the note about line items compensates for the absence of an output schema. Only failure-mode behavior is unaddressed.

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 the schema's hash_key description is already richer than the prose (it warns against using the numeric id and gives a format example). The description adds nothing beyond repeating "by hash_key," so the baseline 3 applies.

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 and resource ("Get one estimate by hash_key") and adds scope (single record plus line items), which implicitly separates it from hiveage_list_estimates and hiveage_create_estimate. It stops short of naming the sibling tools explicitly, so it is clear but not maximally differentiated.

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 only implies usage via "by hash_key" — an agent is expected to infer that this is the retrieval tool when a hash_key is known. It never states when to prefer this over hiveage_list_estimates or what to do without a hash_key, so there is no real when-to-use guidance.

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