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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is fully covered. The description adds one useful behavioral fact beyond annotations — that results are ids intended to be passed to fetch — but says nothing about pagination, result caps, or match quality. With annotations carrying the safety burden, this is adequate but thin.

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 compact sentences, no filler, and the core action plus return contract are front-loaded before the alternative-tool advice. Every clause 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?

For a one-parameter read-only search with no output schema, the description supplies the essential missing piece — that the output is ids to feed into fetch — and annotations cover safety. It stops short of describing result volume or pagination, but nothing critical for a correct call is absent.

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% and the single parameter's description already explains the brand-vs-coin matching behavior in detail. The description merely restates the accepted input types ('brand name, ticker or coin name') without adding format rules or examples the schema lacks, 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 and resource ('Search the impersonation index') plus the accepted input dimensions (brand name, ticker, coin name) and what comes back ('result ids for fetch'). This is clearly more than a restatement of the name, but the purpose sentence itself doesn't differentiate the tool from search_alerts or check_name; that separation only appears in the next sentence.

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?

'Prefer search_alerts / check_name when available' explicitly names alternative tools and gives a condition for choosing them, which is real routing guidance. The condition 'when available' is left undefined, so the agent doesn't know what availability means in practice.

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