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

Annotations already mark the tool as readOnly, idempotent, and non-destructive. The description goes beyond annotations by defining the two return categories ('reachable_workers... these get the push' and 'online_workers... app open this minute') and clarifies that this check happens 'before spending.' This adds meaningful behavioral context beyond the annotations.

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?

The description is two sentences, front-loaded with the core purpose, then the key return semantics, then concrete use cases. Every sentence adds value and there is no filler or redundancy.

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?

Given there is no output schema, the description adequately explains what the tool returns and what the two worker categories mean. It names real-world usage scenarios and positions the tool within the spend flow. The missing radius/location semantics are a gap, but the overall context is sufficient for an agent to decide when to call it.

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 only 33%, with lat and lng having no descriptions. The description does not compensate by explaining coordinate format, radius_m behavior, or how the three parameters relate to 'nearby' or 'physical location.' It only says 'physical location' at a high level, leaving 67% of parameters semantically undocumented.

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?

Description opens with a precise verb and resource: 'Check whether a nearby human can be dispatched to a physical location before spending.' It is clearly distinct from siblings like errand_dispatch and errand_quote because it is positioned as the pre-spend availability check, and it names concrete use cases (photos, queues, pickups).

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 context: 'Use for on-site or store checks, photos, queues, pickups... when you need current human availability.' It implies the tool is a pre-dispatch/pre-spend check, but it does not explicitly say when not to use it or name an alternative such as errand_dispatch. This is strong context without formal exclusions.

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