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

Annotations already establish readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds genuine behavioral context beyond that: the returned fields, and an explicit licensing/attribution obligation (PSI/CC BY 4.0, use attribution.source.statement when citing). It does not discuss result-count or pagination behaviour beyond the limit parameter, which keeps it short of 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?

Front-loaded with what the tool does, followed by the sibling routing, then licensing. Every sentence earns its place, though the licensing sentence is somewhat long and the trailing attribution clause is dense enough to slow parsing slightly.

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?

An output schema exists, so the description need not enumerate return values, and annotations cover the safety profile. The one omission a careful agent might want is any hint about how results are ordered or whether the search is exact-phrase or keyword-AND, but for a simple filtered search this is close to complete.

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%, so limit, query and country are already documented in the schema, including example query strings and the pointer to list_tax_treaty_countries. The description only restates the keyword/country combination without adding format, matching, or syntax detail, so the 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?

States a specific verb (search) and resource (Ireland's double-taxation treaty documents), enumerates what the corpus contains (treaties, protocols, MLI texts), and summarizes the returned fields. It is clearly distinguishable from get_tax_treaty_text, which it explicitly routes the agent to for full text.

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?

Specifies how to find documents ('by keyword and/or country') and names the alternative tool plus the condition that selects it: use get_tax_treaty_text to read the full text rather than searching again. The 'and/or' phrasing also clarifies that query and country can be combined independently.

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