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

Annotations already declare the operation is a non-readOnly, non-destructive, non-idempotent mutation, so the safety profile is covered. The description adds genuinely new context — that the project is scoped to the API key's organization — but says nothing about duplicate names (relevant given idempotentHint=false), permission requirements, or what happens on failure.

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 no filler; the operative action and tenancy scope come first and the conceptual explanation follows. Nothing could be removed without losing content.

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 one-parameter create tool with full annotation coverage, the description supplies the tenancy context an agent needs to call it sensibly. Minor gap: with no output schema, it does not hint at what is returned (e.g., a project identifier needed for subsequent posts_create calls), nor whether names must be unique.

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% for the single required parameter, and the schema already documents "name" as a human-readable project name. The description adds no constraints (uniqueness, length, format) beyond what the schema states, so 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?

Names a specific verb and resource ("Creates a project") and adds tenancy scope: "in the API key's organization." That scope detail distinguishes it from a hypothetical cross-org create, though the description never names the obvious siblings projects_list and projects_delete that an agent might confuse it with.

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 second paragraph explains what projects are conceptually for (isolating social accounts, media, and posts by user/client/brand), which implies when to reach for this tool. However, there is no explicit when-to-use/when-not guidance, no mention of prerequisites such as an existing organization, and no reference to alternatives.

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