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

Annotations already declare readOnlyHint=true and destructiveHint=false, which is unusual for a tool named 'add_event', and the description usefully reconciles this by stating it opens nothing by itself and only returns instructions. It also discloses the external constraint that Bandsintown's official API is read-only, explaining why a browser-based workflow is required. It does not describe the shape or length of the returned steps, authentication state requirements, or failure modes, so it adds moderate value over the annotations rather than rich behavioral context.

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?

Three sentences, front-loaded with the action and its key limitation, with no filler. The middle clause ('Returns how to do it... and opens nothing by itself; then do it with...') is a run-on that takes a second read to parse, which keeps it from a higher score.

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 zero-parameter, no-output-schema tool whose annotations already carry the safety profile, the description supplies what is genuinely needed: that the output is step-by-step guidance and that a separate browser tool chain performs the action. Missing only edge details such as what the steps look like or what to do if the user is not signed in.

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 there is nothing for the description to disambiguate and the baseline of 4 applies. The description's only parameter-adjacent content is the implicit subject (the user's own Bandsintown account), which is context rather than input specification.

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 states a specific action and immediately clarifies the surprising part: the tool does not perform the add itself, it 'Returns how to do it in Bandsintown step by step (screens, buttons, fields) and opens nothing by itself'. That distinguishes it from the cotlet_browser_* siblings, which are named as the actual executors. It stops short of 5 because it does not contrast with bandsintown_update_event or bandsintown_delete_event, so the add-vs-modify boundary is left implicit.

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?

Clear when-to-use context (adding an event to the user's own Bandsintown account) plus an explicit next step ('then do it with the cotlet_browser_* tools in the user's Bandsintown Cloud Browser'). No explicit when-not-to-use or sibling exclusions are given, keeping it below the top mark.

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