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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds only the 'recent/tail' scoping nuance; it says nothing about whether logs stream, truncate, or return empty when no preview is active, which is meaningful for a log-fetching tool.

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 short phrase with the key scoping detail ('recent', 'tail') front-loaded and no filler. It is efficient, though so terse that useful context is omitted rather than wasted.

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 tool with zero required parameters and no output schema, the description leaves important gaps: it does not explain the SSE/streaming nature implied by timeout_ms, what happens when no preview exists, or what the returned log format looks like. The agent is under-informed about invocation context despite the simple schema.

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 both parameters (project_id, timeout_ms) are already documented, including the session fallback. The description adds no additional parameter semantics, so 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 ('Fetch') and resource ('recent preview logs'), and '(tail)' scopes it to the newest entries rather than full history. It is clearly distinct from siblings like get_preview, get_status, or get_health, though it does not explicitly name those alternatives.

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 no when-to-use guidance, no prerequisites (e.g. must a preview be running?), and no mention of alternative tools for status or health checks. The agent must infer usage entirely from the title and parameter names.

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