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

No annotations are provided, so the description carries the full burden. It discloses that this is a free submission step, that payment is required afterward via a separate activation endpoint, and that the blimp rotates ads on every AIARENA game page. It also reveals the return value (ad_id plus tier pricing). It doesn't mention side effects like whether the ad goes live immediately, but the payment step is a key behavioral disclosure.

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?

The description is compact and front-loaded with the key action and resource. It packs a lot of useful information into a few sentences without redundancy. The only minor issue is that the payment instructions are somewhat dense, but they are necessary context.

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?

Given the tool has an output schema and no annotations, the description covers the essential workflow, constraints, and next steps. It doesn't explain the output schema's fields, but the output schema itself likely does that. It also doesn't mention any prerequisites like having an account, but the free submission and payment flow are well covered.

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 0%, so the description must compensate. It adds meaning for all four parameters: name (max 40 chars), website (full URL), tagline (max 60 chars), and email (valid email required). This is strong compensation for the bare schema, though it doesn't give exact formats for website or email beyond 'full URL' and 'valid'.

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?

The description clearly states the tool submits an advertisement for the AIARENA blimp, names the specific resource (aiarena.lol/advertise), and describes the return value (ad_id plus tier pricing). It is distinct from siblings like aiarena_register or aiarena_tournament_create, which handle different resources.

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 description explains the workflow: submit the ad, then pay by POSTing to the activation endpoint with an x402 payment header. It also gives field constraints (name max 40 chars, tagline max 60 chars, valid email required). It doesn't explicitly say when not to use this tool or name alternatives, but the context is clear enough for an agent to know when to invoke it.

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