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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds genuine value beyond them by stating 'Cannot be undone', which sharpens the irreversibility beyond the generic destructive hint. It does not cover error behavior (e.g., cancelling an already-fired schedule) or auth requirements.

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?

Two brief sentences with the action front-loaded and the irreversibility caveat immediately after. Every clause earns its place 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 single-parameter destructive operation whose annotations already convey the safety profile, the description covers what it does and that it is irreversible. No output schema exists and none is needed, though a note on post-cancellation state or failure modes would make it complete.

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 description coverage is 100%, so the single schedule_id parameter is fully documented in the schema. The description adds no format, source, or lookup guidance beyond that, so the baseline 3 applies.

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 ('Cancels a scheduled call'), which is clearly distinct from siblings like call2me_create_schedule and call2me_list_schedules. It stops short of naming those siblings or clarifying the boundary, so it earns a solid 4 rather than a 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?

The description gives no when-to-use guidance, prerequisites, or alternatives (e.g., when to cancel vs. reschedule or update a schedule). The verb implies its purpose, but no routing or exclusion criteria are offered.

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