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

Annotations already declare the safe read profile (readOnly, idempotent, non-destructive), so the bar is lower. The description adds genuinely useful non-obvious behavior: amounts come back as bare numbers with no currency, requiring get_organization_settings to interpret them. It omits output shape and pagination behavior, keeping it from 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?

Two tight sentences with no filler. The purpose is front-loaded and the currency caveat follows as an actionable note, with every clause earning its place.

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 no output schema, the description carries the return-value burden and correctly flags a critical interpretation issue (currency-less amounts). For a simple zero-required-param list tool this is nearly sufficient, though it says nothing about result pagination or item shape.

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% for all four parameters (city, search, page, per_page), including defaults and max values, so the schema does the heavy lifting. The description adds no parameter-level semantics beyond the schema, making the baseline 3 correct.

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 ("List all sites") and clarifies the domain with a parenthetical ("physical locations/campuses") plus scope ("in your organization"). It does not distinguish itself from near-sibling tools like list_locations or get_site, so it stops short of 5.

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 a cross-tool workflow instruction (call get_organization_settings for currency_code before stating an amount), which is real usage guidance. However, it offers no when-to-use/when-not guidance relative to alternatives such as list_locations, get_site, or create_site, so usage is only partially covered.

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