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

With no annotations, the description carries the full burden and discloses the two traits an agent most needs: the engine is deterministic/template-based (no LLM), and each call costs 1 API credit. It also states the return shape is JSON. It does not cover auth requirements, rate limits, or failure behavior, so it falls short of a 5.

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?

Front-loads the trigger condition, then the key behavioral differentiator, then the parameter reference list. No wasted sentences, though the mid-sentence line breaks make the first paragraph read awkwardly.

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, so return values need no prose, and the description still usefully names cost and the deterministic engine. For a simple six-parameter generator the remaining gap is the undocumented required params and any auth expectation, which keeps it from a 5.

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 0%, so the description is the only source of parameter documentation and it does supply the allowed values for tone (warm|bold|professional|playful), platform (linkedin|instagram|tiktok|x), and the count range (1-10). However, the two required parameters, topic and audience, receive no explanation at all, leaving half the contract undocumented.

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 (generate captions) plus the exact output composition — hooks, post bodies, CTAs, hashtags as JSON — and the supported platforms. An agent can distinguish this instantly from siblings check_balance and mint_free_trial, which share no domain.

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?

Opens with an explicit trigger ('Use when the user wants ready-to-post social captions') and adds a clear negative case ('Deterministic template engine (no LLM): best for on-brand, repeatable captions, not open-ended creative writing'). Both the when and the when-not are stated.

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