make_calendar

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

With no annotations, the description fully carries the burden and does so well: it discloses that timezone is accepted but not applied, that the URL is derived from display_name, the collision behavior (nothing created + error names existing calendar), the trash-bin suffix behavior (-2, -3), and the directive to consume the returned URL. This is unusually rich side-effect and edge-case disclosure for a mutation.

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 core action, then ordered by importance: timezone caveat, URL derivation, collision handling, suffix fallback, and the return-URL instruction. Every sentence carries distinct, actionable information with no filler.

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-parameter mutation tool with no annotations and no output schema, the description covers the action, the parameter outcomes, failure/collision modes, and how to consume the response URL. An agent has everything needed to call it correctly and interpret the outcome.

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%, so the baseline is 3; however, the description adds value beyond the schema by explaining the causal relation between display_name and the generated URL and the suffixing rules on collision. It doesn't enrich color/components/description beyond what the schema already says, so it stops short of 5.

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: 'Create a new calendar collection on the CalDAV server,' with the optional fields enumerated. This is unmistakably distinct from create_event/create_todo/create_contact, but the description never names or contrasts a sibling tool, so it earns a solid 4 rather than 5.

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 a genuine when-not rule: if a calendar already exists at the derived URL, 'nothing is created... use it instead of creating another,' and directs the agent to 'Always use the URL returned in the response.' That is clear contextual routing, though it doesn't explicitly compare against update_calendar or other siblings, keeping it below the 5 bar.

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