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

Adds substantial behavior beyond the annotations: login requirement, a 5-minute GET URL TTL, a mandate that the host download bytes with the same MCP credentials, per-call re-verification of file ownership and activity permission, and a no-third-party-forwarding constraint. These are exactly the operational traits (auth, expiry, security) that readOnlyHint/idempotentHint do not convey.

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?

Front-loads the login prerequisite and packs auth, scope, TTL, and security rules into one dense block with essentially no filler. It is slightly run-on, but for a tool with this much behavioral surface the length is justified.

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?

No output schema exists, yet the description explains the return shape (a 5-minute GET address) and the download obligations, plus permission and scope caveats. Combined with the annotations it is complete enough for correct invocation, though pagination or failure-mode behavior is not addressed.

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?

With schema description coverage at 0%, the description must carry the parameters, and it does: slug/key are explained as the file question drawn from get_signup_activity, and submissionId is tied to organizer access sourced from get_signup_submission. It adds meaning and provenance for all three, though it does not spell out format/length expectations.

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: retrieve a download channel for signup file attachments, keyed by slug/key from get_signup_activity. It distinguishes the two scopes (own saved attachments by default vs organizer view via submissionId) and even names the sibling tools that supply the inputs, so the agent can identify it apart from prepare_signup_file_upload or get_activity_material_download.

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?

Gives explicit selection conditions: default path is the caller's own saved attachments, whereas viewing a session's signup-list attachments requires passing submissionId obtained from get_signup_submission. It also states a scope limitation (does not decrypt sensitive ID-document questions), which helps the agent know when this tool is insufficient. No generic when-not-otherwise guidance beyond that.

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