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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description is consistent with that, adding the important context that it 'opens nothing by itself' and only returns screens, buttons and fields. The follow-up requirement (Cloud Browser via cotlet_browser_* tools) is behavior the schema cannot express. It omits failure cases such as what happens when no pending invitation exists.

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 opening sentence is front-loaded and useful, but the closing paragraph about Exercise.com's official API pricing is a tangential boilerplate quote that does not help an agent decide or invoke. The core instruction is also phrased awkwardly ('Returns how to do it ... and opens nothing by itself').

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 parameters, no output schema and annotations covering the safety profile, the description supplies what is needed: what the call yields and which tool family performs the actual deletion. Only edge-case behavior (missing/already-accepted invitations) is left unaddressed.

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?

The tool takes zero parameters, so the baseline is 4; there is nothing for the description to disambiguate. It correctly implies no inputs are needed by describing the call as scoped to the user's own account.

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 ('Delete a pending client invitation in the user's own Exercise.com account') and immediately clarifies that it only returns step-by-step instructions rather than performing the deletion. It does not explicitly distinguish itself from the similar sibling exercise_com_delete_a_client, but the resource scope (pending invitation vs. client) is unambiguous.

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?

Explicitly routes the agent: this tool gives the steps, then 'do it with the cotlet_browser_* tools in the user's Exercise.com Cloud Browser.' That is clear context and a named follow-on alternative. It stops short of stating when not to use it (e.g., invitation already accepted) or any prerequisites, so it is not a full 5.

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