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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context — these events are overlaid on analytics later and should be logged on change observation — but says nothing about auth, whether entries are append-only/editable (update_project_event exists, so that matters), or duplicate handling.

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 front-loaded sentences plus a doc link; the purpose and rationale come first and the examples are dense rather than padded. Slightly trailing API-reference URL is the only structural noise.

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?

Purpose and motivation are complete, and no output schema means return values need no explanation. But for a 12-parameter, 33%-covered write tool with an update sibling, the omission of parameter meaning and edit/immutability semantics leaves real gaps.

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 only 33%. Documented parameters (project, impact, occurred_on, ends_on) are not elaborated in the description, and eight parameters — url, title, client, client_id, project_id, task_id, category, description — are left entirely to the schema. The description does not compensate for the coverage gap.

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 (record) and resource (a significant dated event on a project) and disambiguates with concrete examples — budget change, site migration, campaign launch, outage, external algorithm update. An agent can tell this apart from update_project_event and list_project_events without opening the schema.

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?

"Log one whenever you make or observe a change that will show up in future numbers" gives clear positive when-to-use guidance tied to downstream analytics. It stops short of naming exclusions or the sibling alternatives (e.g., log_project_decision, log_project_issue) that a confused agent might otherwise pick.

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