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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds genuine domain semantics beyond that: an animal with no outcome yet still counts as in the shelter, which changes how results must be interpreted. Rate-limit behavior is only implied via the _apiKey parameter, not narrated.

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 tight sentences: the first establishes the lookup capability, the second the key filter and its semantic consequence. No filler, front-loaded, and the example query phrasing maps directly onto a needed agent behavior.

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 6-parameter, no-required-args read tool with rich schema descriptions and a safety-covering annotation set, the description is nearly sufficient. It does not address what a result row contains or pagination/limit behavior, and there is no output schema to fall back on, leaving a small gap.

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 the baseline is 3. The description earns above baseline by explaining what in_shelter_only actually means operationally ('no outcome yet is still in the shelter'), a nuance that directly affects interpreting the boolean filter and the returned rows.

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 (look up) and resource (animal at Sonoma County Animal Services) with the lookup keys (id, name, breed). It is clearly distinguishable from siblings like sonoma_outcomes_summary and sonoma_recent_intakes, which cover aggregate/history views rather than single-animal lookup.

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?

Gives a concrete usage context: use in_shelter_only=true for 'is there a [breed] at the shelter right now' queries. It does not, however, name an alternative sibling tool or state when not to use this one, so it falls short of full routing guidance.

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