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

The description usefully explains why the tool is not read-only ('Tracks last_checked'), which reconciles with readOnlyHint=false and idempotentHint=false, and discloses the 'Max 3 items' cap and the empty-result shape. It is thin on what a successful non-empty result contains, but it meaningfully extends beyond the annotations.

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?

The content is front-loaded with the core purpose, but the empty-result point is stated twice ('When nothing matches, returns {new:0} — a minimal response when nothing new matches'), and the 'Optional since (YYYY-MM-DD or catalog v)' line largely repeats the schema.

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 burden of explaining returns; it covers the empty case and item cap but never describes the shape or fields of a matched item. For a two-parameter, non-destructive feed tool with annotations present, this is adequate but leaves a real gap.

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 50%: 'since' is documented in the schema, but 'key' is not. The description compensates by explaining 'key' is the same feed key passed to set_preferences and selects that project's profile, closing the main semantic gap.

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 uses a specific verb and resource ('Tools added or updated ... that match their saved tags'), which is clearly distinct from sibling 'search' or 'compare_tools'. It does not explicitly contrast itself with the closest sibling 'whats_new', so it stops short of full sibling differentiation.

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?

There is no explicit statement of when to use this tool versus 'whats_new', 'compare_tools', or 'recommend_tools' — the agent must infer that this is the tag-filtered delta feed. The note 'Does not change recommend_tools' describes a side effect, not a selection criterion.

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