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

Beyond the readOnlyHint annotation, it discloses that the return is a 5-minute GET URL, that the host must download the bytes itself using the same MCP credentials, that ownership and activity permission are re-checked on every access, and that the URL must not be forwarded to third parties. These are non-obvious operational constraints an agent could not infer from the schema or annotations.

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?

It is a single dense, semicolon-linked paragraph that front-loads login and parameter provenance before behavior. Nearly every clause carries information, though the telegraphic phrasing makes it harder to scan than a structured list would be.

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 read-only tool with no output schema, the description covers the input sources, the two access modes, the return artifact (time-limited URL), the download obligation, and the permission re-check. An agent has everything needed to call it correctly and handle the response.

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%, so the description must carry parameter meaning, and it does: slug/key are sourced from get_signup_activity file questions, and submissionId is an optional organizer-only parameter obtained from get_signup_submission. It does not add format guidance for slug or key beyond their origin, which keeps it from a 5.

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?

The description names a specific verb and resource: obtaining a download channel for signup attachments, either one's own or an organizer's view of a specific submission. It distinguishes the two modes (default self-only versus organizer with submissionId), which implicitly separates it from siblings like get_activity_material_download. It stops short of explicitly naming those siblings, so it is not a 5.

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?

It gives prerequisites (login required), the default case (only your own saved attachments), and the alternative case (organizers pass submissionId for this session's signup attachments). It also routes the agent to the correct sources for its inputs: slug/key from get_signup_activity and submissionId from get_signup_submission, plus a scope exclusion that sensitive ID questions are not decrypted.

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