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

With no annotations, the description carries the burden and does add genuinely useful non-schema context: a per-call price ($0.02 USDC via x402). However it is silent on failure modes and on how location is resolved, which matters because all nine parameters are optional and no required location field exists.

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?

A single dense sentence plus a price tag, with the core capability front-loaded and zero filler. Every phrase maps to either a returned data group or a distinguishing claim.

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 nine-parameter tool with no output schema, the description effectively enumerates the response content (prayer times, qibla, restaurants, mosques), which is the main thing an agent needs. It is incomplete only on the edge case of calling with no location and on default behaviors beyond date.

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 baseline is 3, and the description adds marginal value by framing city vs lat/lng as alternatives and by scoping the result set to "today's" prayer times. It still leaves method, cuisine, limit and radius_km entirely to the schema.

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+resource: a bundled lookup returning prayer times, qibla, halal restaurants and mosques for a city or lat/lng. It also distinguishes itself from the individual siblings (prayer_times, qibla, halal_near, mosques_near) by naming exactly which four calls it consolidates.

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?

"Replaces 4 separate calls" gives clear context for when to prefer this over the single-purpose siblings. It stops short of stating the inverse condition — e.g. use prayer_times alone when you only need one data point — so the exclusion is inferred rather than explicit.

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