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

Annotations already cover the safety profile (readOnlyHint=true, idempotentHint=true, destructiveHint=false, openWorldHint=false), so the description's job is to add context, and it does: results are ordered newest first and each entry carries dates, and the source of truth is Staylong's own log. It does not say what happens when no changes exist or whether older changes are retrievable beyond the requested window.

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 sentence with no waste; the resource, scope, ordering, and date inclusion are all front-loaded before any filler.

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 read-only list tool with no output schema, the description covers source, scope, ordering, and that dates are present, which is enough to call it correctly. The remaining gaps are the undocumented 'limit' default and the shape of an individual change entry.

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 0% for the single optional 'limit' parameter, so the schema supplies only type and bounds (1-50). The description never mentions limiting, defaults, or maximum result count; 'latest' and 'newest first' hint at bounded recency but give no concrete semantics.

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 (Thai long-stay visa rule changes), a specific source ('logged by Staylong'), and an ordering ('newest first'), which implicitly separates it from get_visa_rules (current rules) versus this changelog feed. It stops short of naming that sibling explicitly, so the read-versus-changes distinction must be inferred.

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 rather than stated: the word 'changes' suggests this is for tracking what's new rather than for answering 'what are the rules', but there is no explicit when-to-use or when-not guidance and no reference to get_visa_rules or check_visa_eligibility as alternatives.

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