Read a saved contract summary

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description reinforces this with 'without opening a browser or making any network request' — consistent, not contradictory. It goes further by enumerating the returned fields (source URL, extraction time, viewports, element count per viewport, screenshot existence, extraction warnings), which is genuinely useful since there is no output schema. Minor gap: it does not say what happens when the contract file is missing or malformed.

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 tight sentences, front-loaded with the core action and scope, then the usage rationale, then the return shape. Every sentence carries information an agent would otherwise have to guess.

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 a single well-documented parameter, no output schema, and a read-only annotation profile, the description covers the remaining gaps by describing return contents and the no-network behavior. Nothing essential to correct invocation appears missing.

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 contractPath is fully documented in the schema including its link to extract_contract, so the baseline is 3. The description adds no syntax, format, or path-resolution detail beyond what the schema already provides.

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 ('Reads a saved contract file and describes it') and adds a distinguishing negative claim: no browser, no network request. It also names the sibling tool diff_pixels and the condition linking them, so an agent can separate this from extract_contract/check_implementation without opening schemas.

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 gives the usage context ('Use this to inspect what a contract covers') and a concrete decision point ('before deciding whether diff_pixels is possible, since that needs screenshots to already exist'). The alternative and its precondition are stated rather than left to inference.

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