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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds real context beyond them: prices are in THB, results carry durations and master levels (ONE/PRO/PRIME), and keyword matching works across languages. It omits any note on result size, pagination, or empty-result behavior.

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?

Two tightly written sentences: the capability and returned fields come first, then the one actionable parameter hint. No filler, no repetition of the title, and the examples earn their space by showing multilingual matching.

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?

There is no output schema, so the description usefully names the shape of the response (prices, durations, master levels). All three parameters are documented and annotations carry the safety profile. It could be slightly more complete by indicating how results are ordered or bounded.

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 genuinely adds meaning: it explains that q accepts free-text keywords in any language and gives concrete examples ('gel manicure', 'балаяж', 'beard'), which is more than the schema's bare 'Search text'. It says nothing extra about lang or audience beyond their enum values.

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 resource ('Search ERA services') and even enumerates the returned attributes (current prices in THB, durations, master levels), which makes it clearly distinct from generic siblings like search or fetch. It never names a sibling tool explicitly, so it stops short of full differentiation.

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 concrete guidance for the q parameter ('use q for keywords in any language') with multi-language examples, which implies the browse-vs-search modes since no parameters are required. There is no explicit when-to-use/when-not or pointer to an alternative tool such as find_available_slots for booking.

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