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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description still adds real behavioral value by explaining how trending is computed (mentions times a spike against each tag's baseline) and that results merge two distinct sources, which affects how an agent should interpret the output. It does not cover pagination, ordering, or rate limits, keeping it 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?

A single front-loaded sentence naming the resource first, with the methodology and secondary source as trailing clarifiers. Dense but efficient; the parenthetical computation detail is the only element that could be trimmed for a tighter read.

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 three optional parameters and no output schema, the description is adequate on sources and methodology but silent on the shape of returned data (tag name, score, per-network breakdown) and on ordering and limit interaction. For a multi-source aggregation tool, that leaves a meaningful gap an agent cannot resolve from structured fields.

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 67%: window and network carry their own allowed-value descriptions, while limit has no schema description and the tool description says nothing about any parameter. The mention of the three networks loosely corresponds to the network parameter, but no new meaning (units, sorting, default behavior) is added beyond the schema, 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?

The description states a specific resource (trending hashtags) and enumerates the exact sources covered (Bluesky, Mastodon, Nostr) plus Bluesky's native trends list. That verb+resource specificity distinguishes it from siblings like social_trending_links or news_trending_topics without naming them 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?

There is no explicit when-to-use, when-not-to-use, or alternative-tool guidance. An agent must infer from the scope phrase alone that this is the hashtag-trending tool rather than the links, people, or news trending variants listed among siblings.

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