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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the mutation/safety profile is covered. The description adds one genuinely useful behavioral fact beyond the annotations: the update is publicly visible on the project page and in followers' feeds. It does not mention auth requirements or whether updates can be edited or deleted afterward.

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 with zero filler; the action and its visibility consequence are both front-loaded. Every sentence 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?

For a simple 3-parameter write tool with a fully documented schema and no output schema, the description covers the action and its side effect (feed/project-page visibility). Only minor gaps remain, such as whether the post can be edited or removed and whether the id must be a project the caller owns.

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% (id, body, api_key all documented with descriptions and the auth fallback noted), so the schema carries the parameter burden. The description adds no format, length, or content constraints beyond what the schema already states. 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 ('Post a progress update on one of your projects'), which separates it from the generic create_post and from update_project. It does not explicitly name siblings, but the project-scoped framing is clear enough to route correctly.

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?

There is no when-to-use vs when-not guidance or reference to any alternative tool (e.g. create_post for generic posts, update_project for editing the project itself). The 'on one of your projects' phrasing implies scope but leaves the agent to infer when this tool is the right pick.

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