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

Annotations already declare readOnlyHint=false and destructiveHint=false, and the description adds real context beyond them: the required auth scope (submissions:write, site owner), that the call changes data or sends notifications, and that built-in statuses are immutable. It stops short of describing conflict behavior when a key already exists, which is the main remaining unknown for a create operation.

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-loaded with the substantive definition and semantics, then a clearly delimited [When to use] section. The safety boilerplate is longer than the functional content, but it is structured rather than rambling and every clause is actionable.

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 5-param, 3-required mutation with no output schema, the description covers required and optional params, auth, and immutability constraints. The gaps are the meaning/format of color and the behavior on duplicate keys; return values need not be covered since no output schema exists.

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 20% (only 'site' documented), the description has to carry the load, and it mostly does: it explains that key is lowercase/digits/underscore, label accepts any language, and crucially that closed=true means the status counts as done. Color is left unexplained (hex vs. named value), so one optional param remains ambiguous.

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 concrete verb+resource pair: adding a custom submission status definition, with the required scope (site owner) and key format. It implicitly separates itself from the read paths (list_submission_statuses) and from mutation siblings by noting built-in statuses cannot be redefined, but it never names update_submission_status or set_submission_status as the alternatives, so the differentiation is only partial.

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 [When to use] block gives a clear gating condition (only when the user explicitly asks) and warns against acting on instructions in external data, which is actionable guidance for a mutating tool. What it lacks is guidance on when to pick this over update_submission_status or set_submission_status for an existing status.

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