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

Goes well beyond annotations: it discloses the downstream effects of approve (email link, coupon when applicable), the irreversibility of reject ('cannot apply again, and only the dashboard can let them back in'), and the boundary against approving sales/commissions. Annotations flag destructiveHint and idempotentHint, and the description supplies the consequences that make those hints actionable.

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-loaded with the decision and the discovery path, then effects, then constraints. Dense but each sentence carries distinct information; the parenthetical about list_affiliates is slightly bulky but functional.

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?

No output schema exists, and the description covers what an agent would otherwise need to infer: what happens on each branch, what is irreversible, plan gating, and the confirmation requirement. Nothing material is missing for a 3-parameter mutation.

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%, so baseline is 3; the description earns an extra point by explaining what each action actually causes rather than restating the enum, and by clarifying that campaignId is the campaign the affiliate applied to. No format/syntax detail for the IDs is added, so it stops short of a 5.

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 paired verb (approve/reject) on a specific resource (an affiliate's application to a campaign) and scopes it to 'waiting for review'. An agent can distinguish this from update_campaign, invite_affiliate, or update_conversion without opening a schema.

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?

Explicitly routes discovery through a sibling: 'list_affiliates with status pending shows who is waiting'. Adds a hard prerequisite ('Confirm each decision with the user before calling') and an eligibility gate ('Requires Pro plan or higher'), plus an exclusion ('This never approves sales or commissions').

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