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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description only needs to add context — and it does, via input constraints and a pointer to the full output/error contract URL. It does not describe result shape or what happens when zero matches are found, which keeps it short of a 5.

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?

Front-loaded one-line purpose, then labeled blocks, and the constraints that matter are stated up front. Minor waste in placeholder lines ('BEFORE: None', 'DO NOT CONFUSE WITH: None'), though they do cheaply confirm the absence of a prerequisite or sibling overlap.

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?

With an output schema present, the description need not explain return values, and it already covers the input contract, the dependency relationship to downstream tools, and where to find the error contract. Nothing an agent needs to call this correctly is missing.

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 100%, so the schema already documents query, limit, country and response_format. The description restates the same constraints (2-char minimum, 1-10 limit, ISO 3166 alpha-2) without adding format examples or syntax beyond the schema, and omits response_format entirely. 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 transformation: 'Turns a place name into latitude, longitude and IANA timezone.' It also explicitly positions itself against all 100+ siblings ('this is the only place-lookup tool'), so an agent can rule out confusion without inspecting schemas.

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 WORKFLOW block gives explicit before/after routing: BEFORE is 'None' and AFTER names concrete consumers (asterwise_get_natal_chart, asterwise_get_panchanga, asterwise_get_muhurta, asterwise_get_festival_calendar). This tells the agent exactly when to call it and what to do with the result.

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