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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description states 'Read-only' again. More importantly, it adds a behavioral rule beyond annotations: 'never decide for them', clarifying that the tool is for display only and the human must make the decision. This extra context is valuable for the agent to avoid automating approvals.

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?

The description is three sentences, each earning its place: the first defines the resource and its contents, the second covers the optional parameter, and the third gives workflow guidance and read-only status. There is no fluff or repetition, and the most important information is front-loaded.

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 simple read-only list tool with one optional parameter and no output schema, the description is complete: it enumerates what a returned item contains, explains how the playId filter changes scope, and situates the tool in the human-approval workflow. An agent has everything needed to call it correctly and interpret results without additional documentation.

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 coverage is 100% – the schema already describes playId as 'One play; omit for all.' The description repeats this in slightly different words ('One play, or the whole workspace when playId is omitted') but does not add any new semantic details such as value formats, constraints, or behavior beyond the schema. This is a restatement rather than an addition, so it meets the baseline of 3.

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 title and description clearly state the tool's verb and resource: it lists drafted messages awaiting human action, specifically naming the types (invite note, first message, follow-up, reply, comment) and the included context (draft, 'why now', lead, cockpit link). This distinguishes it from siblings like gtm_list_plays (which lists plays) and gtm_approve/gtm_reject (which act on drafts), leaving no ambiguity about what the tool does.

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 description tells the agent when to use this tool: 'Show each draft to the human before gtm_approve / gtm_reject; never decide for them.' This explicitly places the tool in the approval workflow and implies it should be used before any approve/reject call. It does not explicitly enumerate all alternative/not-to-use scenarios, but the context is strong enough for correct selection.

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