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

With no annotations, the description carries the full behavioral burden. It does disclose a genuinely useful provenance trait ('computed by a documented hisab method; not an official Kemenag feed'), but says nothing about return shape, timezone handling, or whether results are cached/computed live.

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 front-loaded sentence with no filler; the scope comes first and the provenance caveat follows as a qualifying clause.

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 simple two-parameter lookup with no output schema or annotations, the description covers purpose, scope, computation method, and the key trust caveat. It would be fully complete if it hinted at what the response contains (the five daily times), but nothing needed to invoke it 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%: both date format and the kecamatan/kelurahan fallback behavior for city_code are already documented in the schema. The description restates 'one kabupaten/kota and date' without adding format or constraint detail, so 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?

Names a specific resource (prayer times) with explicit scope: one kabupaten/kota and one date. No sibling tool covers this domain, so the agent can route to it unambiguously from the name plus description.

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?

Usage is implied by the scope phrase 'for one kabupaten/kota and date', and the Kemenag caveat hints at when to prefer an official source, but there is no explicit guidance on obtaining a valid city_code (e.g., via get_wilayah) or on when-not to use it.

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