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

Annotations already declare readOnlyHint/openWorldHint/non-destructive, so the safety profile is covered; the description adds real value beyond that with the return field set (title, URL, source domain, snippet), a 10-per-page pagination note, and a per-request cost of $0.008. It doesn't mention rate limits or result-quality caveats, but the billing and pagination disclosures are the kind of context annotations can't carry.

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?

Five tight sentences, zero filler, and the highest-value facts (what it searches, what it returns, the Reddit exclusion, cost) are front-loaded. Every sentence earns its place.

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?

With no output schema, the description responsibly covers return shape, pagination size, and cost. It stops short of noting the 10-page cap or sentiment surcharge specifics, but for a 5-param search tool the definition is essentially complete.

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 100%, so every parameter (query, page, time, country, get_sentiment) is already documented in the schema. The description restates the time and country filters without adding syntax or format detail beyond what the schema provides, so the 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?

States a specific verb+resource ('Search forum posts') with a clear scope ('discussion boards, Q&A sites and community forums on the web'). It explicitly distinguishes itself from the nearest sibling by saying 'Use search_reddit for Reddit', so an agent can route without opening either 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?

Names the concrete alternative search_reddit and the condition (Reddit content) that selects it, which is genuine when-not guidance. It does not, however, position itself against other overlapping web/forum-adjacent siblings like search_web or search_news, leaving some routing ambiguity.

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