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

Annotations already state readOnlyHint=true and destructiveHint=false, so the read-only nature is covered. The description adds valuable behavioral detail: it relies solely on coarse location metadata and never on raw user-provided location fields, and results are distance-ranked. This goes beyond annotations by explaining the source and sorting logic.

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?

Three clear, dense sentences with no filler. The primary purpose comes first, followed by the key location-source caveat, then filter options. Every sentence earns its place and no redundant wording appears.

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 read-only tool with five optional params and an output schema (not shown but present), the description covers the essential special aspect (how location is obtained). It omits minor details like return format or no-result behavior, but given the output schema exists and the operation is non-destructive, the context is largely sufficient.

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% — every parameter has a description in the input schema. The description only restates that filters are available ('worship style, denomination, or language'), which adds no new semantics beyond the schema. Baseline 3 is appropriate because the schema carries the param 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 opens with a specific verb and object: 'Find Christian worship churches near the user, ranked by distance.' It further clarifies the unique input mechanism versus siblings by stating it 'Uses only the coarse location metadata ChatGPT shares,' which differentiates it from find_churches_in_city (likely city-based) and get_church (likely specific lookup). No ambiguity remains.

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?

The description gives clear applicable context: use when location comes from ChatGPT's coarse metadata, not raw input fields. It explains behavior when the metadata is city-only. Although it does not name alternative sibling tools or exclusions, the context is explicit enough for an agent to decide when to invoke this tool.

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