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

Annotations already declare readOnly, idempotent, closed-world, non-destructive behavior, so the bar is lower. The description adds value by disclosing the shape of the result (opening hours plus a link to the market guide), which matters since there is no output schema.

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 the resource and default stated up front and the example tacked on at the end. No filler, though the example is somewhat redundant with the schema pattern.

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 single optional-parameter read tool with no output schema, the description covers scope, default behavior, and return contents. Only the absence of alternative-routing guidance keeps it from full marks.

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 coverage is 100% and the date parameter already documents the YYYY-MM-DD pattern, Amsterdam time, and today default. The description largely restates this, adding only a worked example, so baseline 3 is appropriate.

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?

The description names a specific resource and scope: street and food markets in Amsterdam, plus what is returned (hours and a guide link). It doesn't explicitly contrast itself with siblings like whats_on or directory_search, keeping it just below a 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?

Usage is implied by 'open on a day (default today)' plus a concrete example date, so an agent can infer the single-date lookup pattern. There is no explicit when-to-use vs. when-not guidance or pointer to an alternative tool.

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