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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint, so safety is covered. The description adds genuinely new behavioral context: 'Free - it calls nothing', which tells the agent there is no network cost or side effect, plus the no-argument default behavior.

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 purpose and routing guidance before the long enumeration of supported sites. The site list is somewhat bloated but serves real discovery value for an agent judging coverage. Every sentence carries information.

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?

There is no output schema, so the description must convey returns; it does, describing the listing format, the required-parameter marker, and the single-plugin docs mode. Combined with full schema coverage, an agent has enough to call it correctly, though the handoff to run_plugin is not spelled out.

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 goes further by explaining the interaction of the three optional params: no arguments lists all plugins, `category`/`search` narrow the list, and `name` returns one plugin's full parameter docs, plus the '* = required' convention used in the output.

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 ('List ScrapeUnblocker's ready-made site plugins') and immediately clarifies what a plugin is ('scrapers for specific sites that return clean structured JSON'). It also differentiates from the sibling fetch_html by noting a plugin returns data already parsed.

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 the agent: 'Check here before scraping a known site with fetch_html'. That is a clear when-to-use with a named alternative. It does not, however, mention run_plugin, which is the sibling that actually executes a discovered plugin, leaving the discovery-to-execution step implicit.

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