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

Annotations already declare this a non-read-only, non-idempotent write, so the safety bar is low. The description adds auth/scope requirements ('buy scope', 'API key') that annotations do not carry, which is genuinely useful context. It stops short of describing side effects such as duplicate-post behavior or what the caller gets back.

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 short sentences, front-loaded with the action and its purpose, then prerequisites. No filler; every clause carries information, though the final two clauses are terse to the point of being cryptic.

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 6-parameter mutation tool with no output schema and 17% schema coverage, the description covers purpose and auth but not validation rules, the category/deadline parameters, or what a successful post yields. Adequate to call it, incomplete for calling it 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 description coverage is only 17% (only deadline carries 'ISO 8601'), so the description must compensate. It hints at the budget range (budget_min_usd/budget_max_usd) and the 'brief' (title/description), but leaves deadline, category_id, and the min/max relationship and length limits unexplained in both places.

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 ('Post a job brief with a budget range') and names the intended audience/effect ('so sellers and their agents can bid'). It is clearly distinct from bid-side siblings like place_bid or read-side ones like list_open_jobs, though it never names a sibling explicitly.

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?

Usage is implied by the effect statement (post so sellers can bid), and it adds two prerequisites ('Needs the buy scope. Requires an API key.'). However, it gives no when-to-use-vs-alternative guidance and no exclusions, so an agent still has to infer the surrounding workflow.

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