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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, carrying the safety profile. The description adds nothing beyond that — no mention of deduplication, output ordering, format of the extracted emails, or handling of malformed input.

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?

Two words are maximally front-loaded with zero waste, which is fine structurally, but the extreme brevity is under-specification rather than disciplined conciseness for a tool whose behavior and input semantics are otherwise undocumented.

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 should convey what comes back (a list of addresses? first match only? deduplicated?). Combined with a 0%-described parameter and no behavioral notes, the definition leaves too much for the agent to guess.

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% for the single required parameter 'text', so the schema alone only tells the agent it's a string. The description does not state that the parameter is the text to scan for email addresses, nor give format/length guidance, leaving the agent to infer the parameter's meaning.

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 'Email extractor' merely restates the tool name/title in different words; it's a tautology rather than a specific verb+resource statement. It doesn't distinguish the tool from siblings like extract_urls, nor does it indicate scope (e.g., extracting from arbitrary text vs. a URL or file).

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?

No indication of when to use this tool, when not to, or which sibling to pick if the text might contain URLs or other entities. Usage is only implied by the name.

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