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

readOnlyHint=true already tells the agent this is a safe read, so the description's job is only to add context. It discloses the response contents (signers with routing order, status), which is useful, but says nothing about auth requirements, pagination, or error behavior for an unknown eid.

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 tight sentences, zero filler. The purpose and returned fields are front-loaded, with the 'when to use' and GraphQL query name trailing as secondary detail.

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 compensates well by enumerating the returned fields, and it names the GraphQL query. Minor gaps remain around failure modes or how signer status values should be interpreted.

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 schema already explains that eid is the Etch packet eid returned by anvil_create_etch_packet. The description only restates 'by eid' with no additional format or constraint detail, so 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 ('Fetch an Etch e-signature packet by eid') and enumerates the payload returned (status, details URL, document group, signers). It is clearly distinguishable from the sibling anvil_create_etch_packet, which the parameter description even cross-references.

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?

Provides an explicit use case: 'Use this to check signature progress.' That is a clear triggering condition, but it names no alternative tool or when-not condition (e.g., versus anvil_generate_etch_sign_url for signing actions).

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