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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description usefully narrows the mutation surface to exactly two fields, which is consistent with the idempotent hint, but says nothing about failure behavior (unknown track_id), permission requirements, or whether omitted fields are preserved.

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 short sentences, front-loaded with the action and resource, with zero preamble. The second sentence slightly restates the schema but does add the 'only these two fields' constraint, so it still earns its place.

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?

An output schema exists and all parameters are described, so the description needn't cover return values. However, for a mutation tool with no stated error or partial-update semantics, it is only minimally sufficient to call correctly.

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 all four parameters (including the two required IDs) are already documented in structured form. The description restates the two mutable fields without adding format or constraint detail beyond the schema's 'New hex color' and 'New track title' notes, 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+resource ('Update an existing agenda track') and enumerates the two mutable fields, so it is clearly distinct from create_tracks and delete_track. It does not explicitly name those siblings, which keeps it just short of 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?

No guidance on when to use this versus create_tracks, delete_track, or read_agenda, and no prerequisites stated (e.g. that the track must already exist, or that event_id comes from search_events — that fact lives only in the schema). The reader must infer usage entirely.

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